Sound-box for reproducing and recording sound-waves.



R. L. GIBSON.

SOUND BOX FOR REPRODUOING AND RECORDING SOUND WAVES.

APPLICATION YILED JULY 31, 1907.

Patented NOV. 24, 1914.

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45 means of which the diaphragm may ROBERT L. GIBSON, OF PHILADELPHIA, PENNSYLVANIA SOUND-BOX FOR REPRODUCING AND RECORDING SOUND-WAVES. I

Original application filed May 7, 1907, Serial No. 372,432.

Specification of Letters Patent.

Patented Nov. 24, 1914;.

Divided and this application filed July 31, 1907.

Serial No. 386,420.

T all whom it may concern Be it known thatv I ,Ronnn'r L. GIBSON, of the city and. county. of Philadelphia, State of Pennsylvania, have invented an Improve ment in Sound-Boxes for Reproducing and Recording Sound-lVaves, of which the fol-- lowing is a specification.

My inventionhasreferenee to sound boxes for reproducing and recording sound waves, and consists of certain improvements which are fully set forth in the following specification and shown in the accompanying drawings, which. form a partth'ereof.

This application is a division of my application Ser. No. 372,432, filed May 7, 1907.

The object of my invention is to provide a suitablemanner of. supporting the vibrating diaphragm with which the sty lus bar connects, whereby theextreme perimeter or circumferential .edg e 'of the diaphragm will alone be held, in engagement with the ring or easingsof the sound box,1an d by reason of which the vibrationsof the diaphragm will be independent of the elasticity of any intermediate supporting means in the plane of the vibrations such as have been heretofore employed andwvhich cover a materialportion of the faceof the diaphragm.

My invention consists in providing a metallie ring portion which may be secured to or form a part of the case of the sound box I in which the interior diameter is accurately formed, so as to cooperate with the extreme outer edge or perimeter of the diaphragm so as to hold the same definitely in position by a slight clampingaction upon substantially the entire perimeter of the diaphragm, whereby the entire diaphragm is free to vibrate, while at the same time the perimeter is practically held against movement.

More specifically, my invention consists in providing the interior surface of the ring of such a construction that different portions thereof have different diameters, and by be crowded into position so as to be held at its extreme perimeter at one definite place within the ring, and in interposing between the perimeter of the diaphragm and that portion of thering which is to'engage,an exceedingly thin layer of yielding material,

whether of textile or other material, which while not having any material elasticity will form a better binding union between the extreme outer circumference of the diaphragm and the metal ring which supports it.

My invention also comprehends details of construction which, together with the features above s ecified, will be better understood by re erence to the drawings, in which: I I

Figure l is a front elevation of a sound box, embodying my improvements; and Figs. 2, 3 andl are enlarged crossjsections showing definite manners'of uniting the ring and diaphragm, embodying my invention.

A is the metallic ring'i'n which the diaphragm Dis securedl j B is the back which'is attached to'the ring through the medium of screwsC. This back is of the usual 'eons'tructiorr' arid conneets with the flexible tubular-arm'for leading the sound waves to the horn.

D is the diaphragm and is connected with the metallic ring A wholly by pressure exerted upon its extreme circumference or periphery.

E is the stylus bar which is connected at one end with the center of the'diaphragmD and is pivoted at F totlre ring or main frame of the ease of the sound box.

I have shown my invention in connection with the form of thesoun d box commonly sold on the market under the name of the Exhibition box, but it is to be understood that my invention is equally'applicable for use in connection with all soundboxes to which it may be adapted.

The form of the interior of the ring A is preferably such that while of the same cross section transversely to the plane of the diaphragm it has its interior surface formed of different diameters in different parallel planes. This is shown in Figs. 2 and -3 by the groove I and in Fig. 4 by the tapered shape of the interior. \Vhen the groove is used it is made very small and in such case the diaphragm with its interposed layer H of textile or yielding material is crowded into the groove as shown in Figs. 2 and 3, and said diaphragm will retain its position when relieved of the inserting pressure. By use of the groove, however slight, the diaphragm will not be displaced by rough handling during transportation or by jarring should the sound box be dropped.

Referring to Fig. 3, we have the same construction as shown in Fig. 2, but in this case the part of the case in front of the back is formed of two annular parts, namely, the ring proper A and the outer ring A, which latter is secured to the back by screws C and clamps the inner ring A between the parts A and back B. By this construction, new diaphragms with the rings attached may be substituted in the general framing of the sound box without having to insure the screw holes coming into proper position.

In Fig. 4 I have shown the interior surface G of the ring made slightly tapering so as to permit the free entering of the dia phragm D and interposed layer H. and form a strong frictional contact when the parts are adjusted to the proper relative position as shown.

While it is common to employ mica as the material of which the diaphragm is made and while my invention is especially useful with such material, I do not restrict myself to any particular material for the diaphragm as it may be of mineral, vegetable or metal substances as found most desirable.

While I have shown the construction I deemmost preferable in'practice in the cur bodiment of my invention for commercial use, I do not restrict myself to the minor details thereof, as they may be modified without departing from the spirit of the invention.

Any matters herein shown and not claimed either specifically or generically form subject matter of my application aforesaid of which this is a division.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is

1. In a sound box for reproducing and recording sound waves, the combination of a metallic ring structure having its interior surface formed with a continuous or annular groove, a textile material having yielding properties arranged in the ring adjacent to the grooved portion thereof, and a diaphragm having its perimeter locked inthe groove by being forced therein upon the textile material and having its faces free and unobstructed.

2. In a sound box for reproducing and re cording sound waves, the combination of a metallic ring structure having its interior surface formed with an annular groove of small cross section, with a thin layer of yielding material over the groove, a diaphragm having its extreme perimeter forced into retaining engagement with the ring through the yielding material in the plane of the groove, a back plate having a tubular aperture for connection with a horn, an in wardly flanged clamping case ring for clamping the ring holding the diaphragm and centering it, and screws for drawing the case ring to the back extending at right angles to the plane of the diaphragm and arranged outside of the ring holding the diaphragm.

3. In a sound box, the combination with a diaphragm,'of a mounting therefor, a fabric between said mounting and said diaphragm, and frictionallyretained in said mounting to hold said diaphragm in place.

, 4. In a sound box, the combination with a diaphragm, of a mounting therefor and a strip of fabric between the edge of said diaphragm and the-surface of said mounting, said strip being of normally uniform thickness and being frictionally retained by said mounting to hold said diaphragm in place.

5. In a sound box for reproducing and recording sound waves, the combination of a metallic ring structure having its interior surface uniform throughout, with a circular diaphragm having its extreme perimeter alone held by frictional engagement adja-- cent to the interior surface of the ring and under tension, and a compressed layer of textile material between the ring and perimeter of the diaphragm and of a width only slightly greater than the thickness of the diaphragm and greatly less than the width of the ring.

6. In a sound box for reproducing andrecording sound waves, the combination of a metallic ring structure, with a circular diaphragm having its extreme perimeter held by frictional engagement adjacent to the interior surface of the ring and under tension, and a thin textile layer of greatly less width than the ring interposed between the perimeter of the diaphragm and the ring and under compression so as to extend very slightly to opposite sides of the diaphragm whereby the diaphragm is held only at its perimeter and under tension and its entire faces are free and unobstructed.

7. In a sound-box for reproducing and recording sound waves, a diaphragm formed of a flat circular sheet bounded on its periphery by a textile band of a width only slightly greater than the thickness of the diaphragm and secured in position by frictional contact of its textile band with the inner face of the sound box.

8. In a sound box, the combination with a diaphragm of a metallic ring and a thin layer of yielding material interposed between the perimeter of the diaphragm and the inner wall of the ring and held by frictional contact in the ring and holdin the diaphragm by frictional contact wit its perimeter.

9. In a sound box, the combination with a diaphragm of a mounting therefor and a thin layer of yielding material between said mounting and said diaphragm and frictionally retained in said mounting to hold said diaphragm in place.

In testimony of which invention, I have hereunto set my hand.

ROBERT L. GIBSON. Witnesses:

R. M. HUNTER, R. M. KELLY. 

